I am in the exact same position. I am 25 years old and my husband and I would like to have a baby. I've been on the pill since I was 19 and stopped in December. The end of March the dr. put me on Provera and I had a period a week later. I just finished taking Provera again because I still hadn't had another period. My periods were irregular before I went on the pill. I had no idea it would take this long to get regulated. I've talked to other people who said it took them about a year to get straightened out. I'm just getting really impatient. The low estrogen thing sounds like it could be my problem. Did you ever find anything else out???